Improvement in hot-air furnaces



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UNITED STATES PATENT OFrIoE.

EDMUND D. NORCROSS, OF BOSTON, MASSACHUSETTS.

IMPROVEMENT m HOT-AIR FURNACES.

Specification forming part of Letters Patent No. 127,913, dated June 11,1872.

To all whom it may concern:

Be it known that I, EDMUND D. Nononoss, of Boston, in the county ofSuffolk and State of Massachusetts, have made an invention of certainnew and useful Improvements in Hot- Air Furnaces or Stoves; and dohereby declare the following to be a full, clear, and exact descriptionthereof, due reference being had to the accompanying drawing making partofthis specification, and in which Figure 1 is a plan 5 Figs. 2, 3, and4 horizontal sections and Figs. 5 and 6 vertical sections of a hotairfurnace embodying my improvements.

This invention relates to hot-air furnaces or stoves provided with acentral or an internal air-heating passage or flue extending through thefurnace or stove from top to bottom; and it consists in the combination,with a furnace or stove of this character, of an annular grate encirlingthe inner flue, and constructed and arranged to operate substantially ashereinafter described.

The drawing accompanying this specification represents at A the base orash-pit of a hot-air furnace, the door of which is shown at B, such basebeing in the present instance circular in horizontal section, althoughit may be rectangular or polygonal. Within the upper part of the base AI dispose the grate G, such grate being composed of an annular band orring, D, supported upon rollers E E E, pivoted within the base A, asshown, in order that the entire grate may be easily rotated and shaken,the remainder of the grate being composed of two semicircular gratings,F F, which are mounted upon horizontal rods or journals G G, pivoted ateach end within the ring D, the outer extremities of these rodsextending into the doorway of the ash-pit, in order to be readilyaccessible for the purpose of tilting the gratings as occasionrequires,the

said rods converging at front in order that ashes or coals which aredumped from either side of the grate shall be thrown toward the door ofsaid ash-pit. H represents the firepot, which is cylindrical in form,and provided with two fuel-feeding doors, I I, disposed upon oppositesides. J represents the dome of the furnace, which is cylindrical inform,

and is a continuation of the fire-pot, this dome being open at top, andprovided with a smokedischarge flue, K, said discharge-flue beingconstructed with a bent-pipe, L, which constitutes an indirect flueafter the manner of many furnaces now in use. M in the drawing Yrepresents a vertical open cylinder or pipe, which is erected upon thebottom of the ashpit and opening through the same, such cylinder risingupward within the center of the fire-pot and into the dome, and unitingwith the latter at its extreme upper part, by this means producing adouble radiating surfacean inner and outer one. N represents ahorizontal shield or deflector, placed within the upper part of the domeJ, for the purpose of deflecting the smoke and waste products ofcombustion from the smoke-flue K, and compel them to take an indirectcourse before escaping thereat.

Owing to the annular form of the fire-pot, as herein shown, I prefer toemploy two fuelfeeding apertures for the sake of convenience,

although two are not absolutely necessary. By the employment of the twogratings, of which the grate is composed, I am enabled to partially dumpor to clear one half of the fire,

while the other remains undisturbed, while at the same time the entiregrate may be partially revolved or shaken,'as with ordinary grates. Inaddition to the opening through the bottom of the ash-pit, the cylinderM may receive air through a horizontal branch-pipe, O, which extendsthrough the wall of the ashpit, as represented, and is contracted at topin order to prevent collection of soot and ashes.

When a small amount of fire is required, the annular fire-pot may bedivided by suitable partitions, and the use of one half discontinned.

With regard to the inner circulating flue or passage M I would remarkthat its precise form or position is not an arbitrary one, since in lieuof being disposed centrally of the firepot or dome it may be placed toone side thereof, and may be a part of said fire-pot, and casthomogeneous therewith, as shown in Fig. 4 of the drawing. I would alsoremark that I contemplate the employment of double or extensionpartitions in the annular fire-pot to divide the same for purposesstated or to utilize a greater or less portion thereof according to theamount of fire desired.

Claims.

I claim- 1. In combination with the inner flue M, before named, and thesurrounding fire-pot, a grate, composed of two segmental gratings,pivoted to a common ring or band which is capable of revolving withinthe upper part of the ash-pit, as and for the purposes stated.

2. I also claim the arrangement of the segmental gratings upon rods orjournals converging toward the door of the ash-pit, as and for thepurposes described.

EDMUND D. NOROROSS.

Witnesses FRED. OoR'rIs, W. E. BOARDMAN.

